Operating systems executing on a computing device may expose APIs (Application Programming Interfaces) to applications that enable an application to request computing environment information for the computing device. For example, an application may obtain information related to a computing device's hardware, file systems, processing events, graphical user interface, etc. For instance, when an application is opened on a computing device, the operating system may be queried via an API to determine screen size dimensions for the computing device's display. In some cases the screen size dimensions returned may be the actual screen size of a computing device display and not an available screen area that accounts for operating system generated graphical user interfaces (e.g., a status bar, a tool bar, a start bar, etc.) that may be displayed on the computing device display.
Some computing devices may include a base operating system that provides one or more graphical user interfaces and a shell operating system that may provide additional graphical user interfaces. For example, a computing device may execute a base operating system that may be the lowest level of hardware management on a computing device, as well as an operating system shell that interfaces with the base operating system. Graphical user interfaces and related graphical user interface controls provided by a base operating system, as well as a shell operating system, that are displayed on a computing device may reduce an amount of screen space available to display an application when the graphical user interfaces are displayed in combination with an application.